This invention relates to a multifocal lens and eyeglasses having a vision correction assembly, montage, and/or arrangement which consists of two integrated bifocal or trifocal lens regions and a far-distance vision correction region.
In the ordinary use, arrangement, application and/or mounting of bifocal and trifocal lenses, the segments for near-vision and intermediate-distance correction are usually arranged in the lower portion of prescription lenses, thus requiring the wearer to raise his head or neck and direct his eyes to the lower part of the lens to view nearby or intermediately-distanced objects that are located or displayed at or higher than the user's eye level. For instance, in applications associated with carpenters', plumbers' or contractors' professions, it is usually desirable to look through the near-distance corrective segment of a bifocal or trifocal lens, or through the intermediate-distance corrective segment of a trifocal; but then it becomes necessary to cast the head back to focus on the object and position the eyes downward to gaze through the desired lens segment when something is at or above a user's eye level. A similarly strained position must be assumed to view a computer screen, at or above eye level, through the near or intermediate-distance correction and magnification range of a user's lens. The process is particularly arduous when a person seeks to read a document placed below eye level, for instance atop a desk, and alternatively to read on a screen, at or above eye level, what he may be typing on a computer.
To obviate the foregoing disadvantages, the construction of lenses adapted to be turned through auxiliary frames, in their bearings, via various types of swivel, locking, sliding and/or spring mechanisms and connections, and/or with each lens moving simultaneously or independently or towards a desired direction of focus have been proposed. See U.S. Pat Nos. 772,196; 1,085,522; and 2,390,825. Also the use of multiple lenses has been proposed. See U.S. Pat. No. 1,585,489. For applications in work locations with which a computer screen is associated, or for activities associated with cash registers, larger near-vision and variously-shaped near-distance correction segments have been proposed to increase near-distance correction and magnification. See U.S. Pat. No. 4,690,524. Further, detachable eyeglass frames with lenses specially placed and/or distanced from the eyeglass for specialized occupations have been proposed for purpose of accommodating sports, medical and other enumerated occupations similar to those subject of the present invention, with the simultaneous objects of: Utilizing a detachable intermediate-distance corrective lens atop any type of eyeglass, including bifocals and trifocals; to provide a full field of view for any correction, for users who cannot adapt to wearing bifocal or trifocal lenses constantly; and to avoid the diminishment of the field of view for any correction. See U.S. Pat. No. 6,027,214. Additionally, where bifocal or trifocal lenses are not desirable, disposable lens shields and “press-on” lenses in the upper and/or upper-central regions of the lens have been proposed. See U.S. Pat. No. 3,033,359; PCT Int'l App. PCT/US 94/14271.